From: Peter Zijlstra <peterz@infradead.org>
To: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: tglx@linutronix.de, mingo@redhat.com, luto@kernel.org,
paulmck@kernel.org, muchun.song@linux.dev, bp@alien8.de,
dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 05/11] smp: Enable preemption early in smp_call_function_many_cond
Date: Thu, 5 Feb 2026 10:52:36 +0100 [thread overview]
Message-ID: <20260205095236.GI232055@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260203112401.3889029-6-zhouchuyi@bytedance.com>
On Tue, Feb 03, 2026 at 07:23:55PM +0800, Chuyi Zhou wrote:
> + /*
> + * Prevent the current CPU from going offline.
> + * Being migrated to another CPU and calling csd_lock_wait() may cause
> + * UAF due to smpcfd_dead_cpu() during the current CPU offline process.
> + */
> + migrate_disable();
This is horrible crap. migrate_disable() is *NOT* supposed to be used to
serialize cpu hotplug.
next prev parent reply other threads:[~2026-02-05 9:52 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-03 11:23 [PATCH 00/11] Allow preemption during IPI completion waiting to improve real-time performance Chuyi Zhou
2026-02-03 11:23 ` [PATCH 01/11] smp: Disable preemption explicitly in __csd_lock_wait Chuyi Zhou
2026-02-05 6:05 ` Muchun Song
2026-02-03 11:23 ` [PATCH 02/11] smp: Enable preemption early in smp_call_function_single Chuyi Zhou
2026-02-05 3:55 ` Muchun Song
2026-02-05 9:34 ` Peter Zijlstra
2026-02-03 11:23 ` [PATCH 03/11] smp: Remove get_cpu from smp_call_function_any Chuyi Zhou
2026-02-05 6:03 ` Muchun Song
2026-02-05 9:42 ` Peter Zijlstra
2026-02-06 8:54 ` Chuyi Zhou
2026-02-03 11:23 ` [PATCH 04/11] smp: Use on-stack cpumask in smp_call_function_many_cond Chuyi Zhou
2026-02-05 9:44 ` Peter Zijlstra
2026-02-06 9:07 ` Chuyi Zhou
2026-02-05 9:51 ` Peter Zijlstra
2026-02-03 11:23 ` [PATCH 05/11] smp: Enable preemption early " Chuyi Zhou
2026-02-05 9:52 ` Peter Zijlstra [this message]
2026-02-05 10:57 ` Peter Zijlstra
2026-02-05 14:29 ` Chuyi Zhou
2026-02-05 14:59 ` Peter Zijlstra
2026-02-06 8:43 ` Chuyi Zhou
2026-02-06 9:47 ` Peter Zijlstra
2026-02-06 11:45 ` Chuyi Zhou
2026-02-09 7:56 ` Chuyi Zhou
2026-02-03 11:23 ` [PATCH 06/11] smp: Remove preempt_disable from smp_call_function Chuyi Zhou
2026-02-03 11:23 ` [PATCH 07/11] smp: Remove preempt_disable from on_each_cpu_cond_mask Chuyi Zhou
2026-02-03 11:23 ` [PATCH 08/11] scftorture: Remove preempt_disable in scftorture_invoke_one Chuyi Zhou
2026-02-03 11:23 ` [PATCH 09/11] x86/mm: Move flush_tlb_info back to the stack Chuyi Zhou
2026-02-03 11:24 ` [PATCH 10/11] x86/mm: Enable preemption during native_flush_tlb_multi Chuyi Zhou
2026-02-03 11:24 ` [PATCH 11/11] x86/mm: Enable preemption during flush_tlb_kernel_range Chuyi Zhou
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